Corner and junction assemblies for service provision ducting and components therefor

ABSTRACT

In order to provide designs of corner and junction assemblies for service provision ducting which are simple to construct and do not require a large number of components, there is provided an internal angle cover part  22, 28, 31 , an external angle cover part  21  and a straight wall cover part  36 . These can be combined together to form a flat bend (FIG.  4 ), a cross-over (FIG.  5 ) or a flat T (FIG.  6 ). Each cover part comprises a cover surface  22, 23, 28, 35  which extends up to, but no further than the centre line of the respective section of service provision ducting.

[0001] The present invention relates to corner or junction assembliesfor service provision ducting and to components therefor.

[0002] Ducting for providing for example electrical and communicationsservices is widely used within buildings. Such ducting particularlycomprises a longitudinally extending channel of an indefinite lengthdefined by a longitudinally extending base member and at least onelongitudinally extending wall member projecting from the base member.The ducting may be further divided into parallel co extending channelsof indefinite length divided by a longitudinally extending internal wallmember projecting from the base member. This division of ducting intoparallel channels is referred to as “segregation”. Ducting normallycomprises at least one cover member for closing the open face of theducting so that, in use, the conductors or communication cablescontained within the ducting are protected from contamination orcontact.

[0003] The ducting may comprise trunking which may be mounted on wallsor floor extending in a horizontal or vertical direction. The line ofthe ducting may include at least one flat bend, in which a pair ofsections of service provision ducting meet at an angle with the floormembers of sections of service provision ducting substantially coplanar.The line of ducting may include at least one junction, where three ormore sections of service provision ducting meet, with the floor membersof all the sections of service provision ducting being in substantiallythe same plane. The junction may comprise for example a flat T, athree-way junction or a four-way junction or cross over.

[0004] There are a number of known ways of constructing flat bends, flatT's and flat junctions. The present invention is concerned however, withproviding a cover member for covering the flat corner, flat T or flatjunction it is known to provide a cover for a corner, flat T or junctionby providing a single cover member which covers all for the sections forservice provision ducting at the point where they meet. Such covers aregenerally large and difficult to manufacture. In order to provide coverstructures for all types of junction, a large number of different typesof component are required.

[0005] It is known to provide a cover member for a junction by takingcover parts which are normally used for sections of service provisionducting and cutting them to an appropriate shape. However, this can becomplex and time consuming for installers.

[0006] The present invention sets out to provide a corner or junctionassembly for service provision ducting which includes cover memberswhich are simple for manufacture and install. Further, the presentinvention sets out to provide flat corner or junction assemblies forservice provision ducting which includes cover members, and which do notrequire a large number of different components.

[0007] The present inventors have realised that cover parts can beprovided which extend from the angle between adjacent sections ofservice provision ducting up to the centre line of each section ofservice provision ducting. Such cover parts are simple to manufactureand not bulky. The cover parts can meet one another, or another covermember at or near the centre line of the service provision ducting. Inthis way, the corner or junction can be assembled with cover parts in asimple way.

[0008] In the description that follows, the term “internal angle” willbe used to mean an angle defined between two sections of serviceprovision ducting which meet at a flat bend or junction, which angle isless than 180°. The term “external angle” will be used to define theangle between two sections of service provision ducting which meet in aflat bend or junction, which angle is greater than 180°.

[0009] The present inventors have further realised that a cover part foran internal angle of a flat surface can be used in a variety ofdifferent structures, for example in a flat corner or in a T-junction orin cross over, as will be further explained below. In this way, it hasbeen found that a number of simple parts can be used to build up anyrequired structure.

[0010] The present invention accordingly provides a corner or junctionassembly comprising at least two sections of service provision ductingmeeting at an angle, each section comprising a longitudinally extendingfloor member and at least one longitudinally extending wall memberprojecting from the floor member, the floor members of the sections ofservice provision ducting being substantially co-planar, and adjacentsections of service provision ducting defining between them an angle, acover part being provided extending from each angle up to, but nofurther than, the centre line of the respective sections of serviceprovision ducting.

[0011] The present invention further provides a method of assembling acorner or junction assembly for service provision ducting, comprisingplacing at least two sections of service provision ducting at an angleto one another, each section comprising a longitudinally extending floormember and at least one longitudinally extending wall member projectingfrom the floor member, the floor members of the sections of serviceprovision ducting being substantially coplanar and adjacent sections ofservice provision ducting defining between them an angle, the methodfurther including the step of inserting a cover part which extends fromeach angle up to but no further than the centre line of the respectivesections of service provision ducting.

[0012] The present invention further provides a component for a corneror junction assembly as defined above, the component comprising a cornersurface and a cover surface extending from the corner surface, wherebyin use, the corner surface is located in the angle between two sectionsof adjacent service provision ducting and the cover section extends fromthe angle up to but no further than the centre line of the respectivesections of service provision ducting.

[0013] In order to form a flat bend or corner, the assembly willcomprise two sections of service provision ducting meeting at an angle,the sections of service provision ducting defining a first, internalangle and a second, external angle, there being a first cover partextending from the internal angle and a second cover part extending fromthe external angle. Preferably, each cover part comprises a cornersurface and a cover surface extending from the corner surface. The endsof the sections of service provision ducting may be cut at an angle totheir longitudinal direction, to form a mitre. Alternatively, onesection of service provision ducting may abut against the side of asecond piece of service provision ducting, a wall member of the secondsection of service provision ducting being removed at the position wherethe first section of service provision ducting abuts it.

[0014] Preferably, the corner surface comprises a curved surface, theradius of curvature of the curved surface being not less than apredetermined value. The assembly of the present invention may be usedin service provision ducting which carries communications cables. It isnormally required that such communications cables should not be bentthrough a curve of radius less than a specified value, in order toprevent loss of signal quality. The predetermined value is normally inthe range 25-75 mm and is normally specified by the manufacturer of thecables. If the sections of service provision ducting are not continuedto the corner, a part of the bend will in fact be defined by the coversurface of each cover part. Preferably, accordingly, the radius ofcurvature of the corner surface of the cover part is not less than avalue falling in a range 25-75 mm.

[0015] Suitably, the bend is a 90° bend.

[0016] In order to form a flat T junction, the assembly may comprise afirst section of service provision ducting and a second section ofservice provision ducting which abuts the side of the first section ofservice provision ducting, a section of a wall member of the firstsection of the service provision ducting being removed, whichsubstantially corresponds in size and position to the width of thesecond sections of the service provision ducting, the first and secondsection of service provision ducting defining between them two internalangles. Further, opposite the internal angles, there is a straight sideof the first section of service provision ducting. Alternatively, a flatT-junction may be formed by placing two sections of service provisionwhich extend substantially in line with one another and a third sectionof service provision ducting abutting the two sections of serviceprovision ducting at the zone where they meet. The ends of the twosections of service provision ducting may meet or they may be displacedfrom one another. The ends of the two sections of service provisionducting and the third section of service provision ducting may be cut atan angle to their longitudinal direction to form a mitre shape T. In allcases, the third section of service provision ducting defines twointernal angles with the other two sections of service provisionducting. Opposite the two internal angles, there is a straight side.

[0017] Suitably, in all cases, there is a first cover part extendingfrom the first internal angle, a second cover part extending from thesecond internal angle and a third cover part extending from the side ofthe service provision ducting opposite the junction. Suitably, thejunction is a right angled flat T junction. In this case, the first andsecond cover parts may be substantially identical to one another.

[0018] Preferably, the first and second cover parts each comprise acorner section and a cover section extending from the corner section.Preferably, the corner section of each cover part comprises a curvedsection which is of a radius of curvature not less than a value fallingin the range 25-75 mm, for the reasons explained above. Suitably, thefirst and second cover parts are substantially identical to the internalangle cover part used in a flat bend of 90°. Suitably, the third coverpart comprises a wall section and a cover section extending from thewall section.

[0019] In order to form a four way junction or cross-over, there is apreferably a first section of service provision ducting, a secondsection of service provision ducting meeting the first section ofservice provision ducting on a first side thereof and a third section ofservice provision ducting meeting the first section of service provisionducting on the opposite side. Sections of wall members of the firstsection of service provision ducting corresponding in size and positionto the third and second sections of service provision ducting may be cutaway. Alternatively, the four-way junction may be defined by foursections of service provision ducting. Two sections of service provisionducting which meet end to end and which extend along substantially thesame straight line may be provided, two other sections of serviceprovision ducting abutting the sides of the first two sections ofservice provision ducting. The sections of service provision ducting mayextend towards one another but stop short of one another to form an openspace between them. Alternatively, four sections of service provisionducting may be provided which are cut at their ends to form triangularpoints, to form a mitre junction. In all cases, the sections of serviceprovision ducting, define between them four internal angles. Preferably,a cover part extends from each internal angle.

[0020] Preferably, sections of service provision ducting meet at anright angle. In this case, all of the cover parts may be identical toone another. They may be identical to the cover part used in a flat bendinternal angle. Each suitably comprises a corner section and coversection extending from the corner section.

[0021] Preferably, each corner section comprises a curved section ofradius of curvature not less than a value falling in the range 25-75 mm,for the reasons set out above.

[0022] Any number of sections of service provision ducting may meet toform a flat junction. Where they meet, they will define internal anglesbetween them. Cover parts may be provided for extending from internalangles extending up to the centre lines of the sections of serviceprovision ducting which define the internal angle.

[0023] It can be seen that, if an internal angle cover part, an externalangle cover part and a flat wall cover part are provided, a cover can beprovided for a right angle flat bend, a right angle T junction or aright angle cross over using a very small number of different parts.This provides a very flexible system which is simple to install and use.

[0024] Preferably, in each case, the cover part extends up to the centrelines of the sections of service provision ducting between which itlies. In this way, when assembled, the cover sections of all the coverparts used in the assembly will meet at the centre lines of respectivesections of service provision ducting.

[0025] It is, however, possible that the cover section will not extendas far as the centre line, in which case, a further cover part, forexample, a lid structure, may be provided to close the top of thejunction between the cover sections.

[0026] The service provision ducting used in the present inventionpreferably comprises at least two longitudinally extending wall membersprojecting from the wall member, defining between them a longitudinallyextending channel.

[0027] The present invention may be used with sections of serviceprovision ducting which include at least one dividing member whichextends substantially along the centre line of each section of serviceprovision ducting. Suitably, this central dividing wall comprisesengaging means along its top edge. In this case, the cover sections mayeach be provided with engaging means for engaging in the engaging meansof the central dividing wall.

[0028] Means may be provided for engaging one cover section to anadjacent cover section. However, where each may be separately connectedto the central dividing wall, there is preferably no direct connectionbetween adjacent cover sections. Engagement means may be provided on thecover sections for engaging outer wall members of the sections ofservice provision ducting.

[0029] The corner or junction assembly of the present invention isparticularly suitable for use with radiussed inserts or base members.This is particularly required where the ducting is intended to carrycommunications cables, particularly fibre optic cables. Due to theinternal design of such cables, it is important not to bend them in sucha way that they have a radius of curvature less than a given amount,which is normally from 25 mm to 75 mm, with 50 mm being typical. Theactual value will be determined by the respective physical properties ofthe cable and is specified by the manufacturer. In a flat bend of knowntype, the walls of the sections of service provision ducting meet atright angles where the radius of curvature is much less than thespecified amount and is therefore unsuitable for use for fibre opticcables. Preferably, a corner piece is provided extending between twosections of service provision ducting, the corner piece comprising asurface having a first end lying on the wall member of the first sectionof service provision ducting and a second end lying on a wall member ofthe second section of service provision ducting, and a curved section ofradius not less than a value in the range 25-75 mm joining the first andsecond ends of the corner piece, at least one rib being provided havinga straight edge projecting from a rear surface of the corner piece andlying against a wall member of the first or second section of serviceprovision ducting. The corner piece may be provided for an internalangle, in which case the curved section extends over an angle which issuitably in the range 30-120°, more preferably about 90°. A corner piecemay be provided for extending around an external bend between twosections of service provision ducting, in which case, the curved sectionextends through an angle in the range 200°-300°, preferably around 270°.

[0030] It is known to provide longitudinally extending engagement meansprojecting from the floor member of a section of service provisionducting. These are provided for supporting within the ductinglongitudinally extending electrical conductors (commonly called busbars)or electrical or optical communications cables. Preferably, the cornerpiece is provided with slots for engaging over these engagement members.Accordingly, the corner piece preferably comprises a surface having afirst end lying on the wall member of a first section of serviceprovision ducting and a second end lying on the wall member of a secondsection of service provision ducting and a curved section of radius inthe range 25-75 mm joining the first and second ends, at least one edgeof the curved section extending between the ends comprising at least oneslot engaging around an engagement member of a respective section ofservice provision ducting.

[0031] The service provision ducting may be made of cast, moulded,formed or extruded material, for example thermoplastic or metal,particularly uPVC or aluminium. Suitable ducting is described forexample in GB-A-2253096 and GB-A-2282278.

[0032] The cover parts may be made of cast, formed, moulded or extrudedmaterial in the same way.

[0033] The present invention will be further described with reference tothe accompanying drawings, in which:

[0034]FIG. 1 is a schematic plan view of a flat bend formed from twosections of service provision ducting.

[0035]FIG. 2 is a schematic plan view of flat T-junction formed betweentwo sections of service provision ducting.

[0036]FIG. 3 is schematic plan view of a cross-over formed between threesections of service provision ducting.

[0037]FIG. 4 is sketch plan view of a corner assembly according to theinvention.

[0038]FIG. 5 is sketch plan view of cross over junction according to thepresent invention

[0039]FIG. 6 is sketch plan view of a flat T-junction according to thepresent invention.

[0040]FIG. 7 is sketch isometric view of flat bend formed in a known wayusing two sections of service provision ducting.

[0041]FIG. 8 is a sketch isometric view of a first embodiment ofstraight wall cover part for use with the present invention.

[0042]FIG. 9 is sketch isometric view of a first embodiment of aninternal angle cover part for use with the present invention.

[0043]FIG. 10 is a sketch isometric view of a first embodiment of anexternal end cover part for use with the present invention.

[0044] FIGS. 11-13 show sketch views of a second embodiment of externalangle cover part according to the present invention.

[0045] FIGS. 14-17 are sketch views of a second embodiment of internalangle cover part according to the present invention.

[0046] FIGS. 18-21 are sketch views of a second embodiment of straightwall cover part for use with the present invention.

[0047]FIG. 22 is a sketch plan view of an internal angle cover part andan external angle cover part assembled together with a corner piece.

[0048]FIG. 23 is a sketch view of the underneath of FIG. 22.

[0049]FIG. 24 is a sketch view of the underneath of a flat T formedusing two internal angle cover parts and one straight wall cover partand four corner pieces.

[0050]FIG. 25 is a sketch plan view of the top of FIG. 24.

[0051]FIG. 26 is a sketch plan view of a right angle cross over formedusing four internal angle cover parts and four corner pieces.

[0052]FIG. 27 is a sketch view from the underneath of FIG. 26.

[0053]FIG. 28 is a sketch plan view of a corner piece as used in FIGS.22-27.

[0054]FIG. 29 is a sketch plan view of a corner piece used in FIGS.22-27.

[0055]FIG. 30 is an isometric view of the corner piece FIG. 28.

[0056]FIG. 31 is an isometric view of the corner piece of FIG. 29.

[0057] FIGS. 1-3 show known ways of forming various types of structureusing service provision ducting.

[0058]FIG. 1 shows two lengths of service provision ducting which meetat a right-angled corner. Each length of service provision ductingcomprises a longitudinally extending floor member 2 and a pair oflongitudinally extending wall member 3 which extend upwards from thelongitudinally extending floor member 2. They are shown double thicknessfor clarity in FIG. 1. Further, each section of service provisionducting comprises a longitudinally extending dividing wall 4 whichextends along the centre line of the section of service provisionducting. The ends of the sections are cut at a 45° angle so that theyform a 90° mitre bend along the line 5.

[0059] In FIG. 2, two lengths of service provision ducting are joined toform a flat T. Each length of service provision ducting is of the sametype as shown in FIG. 1 and is numbered accordingly.

[0060] The first section 6 of service provision ducting, extendscontinuously from left to right. The second section, 7, terminatesagainst the side of the first section 6. At the position where thesecond section terminates, the wall 3 of the first section 6 has beencut away to allow free communication between the lower channel 8 of thefirst section 6 and the channels 9 and 10 of the second section 7.

[0061] In FIG. 2, the first right angle A and the second right angle Bare defined between the first and second sections of service provisionducting 6 and 7.

[0062]FIG. 3 shows how three sections of service provision ducting maybe joined together to form a cross-over. Each section is substantiallyas shown in FIG. 1 and is similarly numbered. A first section 11 extendscontinuously from left to right. The other two sections, 11 and 12, meetthe first section on opposite sides. At the positions where the secondand third sections 12 and 13 terminate, the wall 3 of the first section11 has been cut away so that there is communication between the topchannel 14 of the first section 11 and the channel 15 and 16 of thesecond section 12 and free communication between the lower channel 17 ofthe first section 11 and the channels 18 and 19 of the third section 13of service provision ducting.

[0063] In FIG. 3, right angles C, D, E and F are formed between thesections of service provision ducting.

[0064]FIG. 4 shows a corner structure according to the presentinvention. It comprises a corner as shown in FIG. 1. In the cornerregion, it is covered by a cover structure which comprises a first,internal angle cover part 20 and a second, external angle cover part 21.

[0065] The cover part 20 includes a cover surface 22 which extends up tothe centre line (defined by the central dividing wall 4) of the firstand second sections of service provision ducting. Similarly, theexternal angle cover part 21 comprises a cover surface 23 which extendsup to the centre line. At the centre line, the internal and externalangle cover parts 20 and 21 meet, forming a complete cover.

[0066]FIG. 5 shows four internal angle cover parts 24, 25, 26 and 27,extending from the right angles C, D, E and F.

[0067] Each of the internal angle cover parts 24-27 is identical to thecover part 20 shown in FIG. 4. Each comprises a cover surface 28 whichextends up to the centre line of the first section of service provisionducting 11 and up to the centre line 30, or the continuation thereof, ofthe second and third sections of service provision ducting 12 and 13.

[0068] The cover surfaces 28 of the internal angle cover parts meetalong the centre lines 29 and 30 to form a complete, closed cover forthe cross-over.

[0069]FIG. 6 shows a T junction assembly according to the invention. Itemploys a flat T as shown in FIG. 2. A pair of internal angle coverparts 31 and 32 are provided extending from the right angles A and B.Each comprises a cover surface 35 which extends up to the centre line 33of the first section 6 of service provision ducting and up to the centreline 34, or notional continuation thereof, of the second section ofservice provision ducting, 7.

[0070] On the opposite side to the right angles A and B, a straight wallcover part 36 is provided which extends up to the centre line 33 of thefirst section of service provision ducting. Along the centre lines 33and 34, the cover parts meet, forming a closed cover.

[0071] The internal angle cover parts 35 are identical to the internalangle cover part 20 and the internal angle cover part 24-28 of FIGS. 4and 5.

[0072]FIG. 7 shows an isometric view of the flat corner shown in FIG. 1.It has already been described with reference to FIG. 1 above.

[0073]FIG. 8 is a sketch isometric of view of the straight wall of coverpart 36 of FIG. 6. It comprises a wall part 37 and a cover surface 38which extends from the wall part 37.

[0074]FIG. 9 is a sketch isometric view of an internal angle cover partaccording to any of FIGS. 4,5, and 6. It comprises a corner surface 39and cover surface 40 extending from the corner surface 39.

[0075]FIG. 10 is a sketch isometric view of a external angle cover partas used in FIG. 4. It comprises a pair of external angle walls 41 whichmeet one another at a right angle and a cover surface 42 which extendsfrom both external angle cover walls 41.

[0076]FIG. 11-13 shows views of a second embodiment of external anglecover for use in the present invention. It is similar in design to FIG.10. However, it includes a first set of clips 43 which are configured toengage with the top of the wall of service provision ducting for exampleas shown in FIG. 7. There is a second set of clips 44 for engaging thetop of wall member of a second section of service provision ducting.There is a cover surface 45 which corresponds to the cover surface 42 ofFIG. 10. At its internal periphery, the cover surface 45 comprises a lipwhich extends along one edge and then along a second edge at rightangles to the first edge. This lip is provided to rest against acorresponding lip of other cover parts so that a secure closure can beformed between the cover parts. A set of clips 47 are provided. Thesegrip together with the lips 46, a flange of a central dividing wall ofsection service provision ducting which has a double flange at the topof its central dividing wall.

[0077] FIGS. 14-17 shows sketch isometric views of a second embodimentof internal angle cover part according to the invention. It is similarin design to FIG. 9, but includes the following additional features. Afirst clip 48 and a second clip 49 are provided for engaging the tops ofwall members of sections of service provision ducting. A pair of lips50, 51 are provided for engaging against the corresponding lip and of anadjacent cover part. Clips 52 are provided for engaging, together withthe lips 50 and 51, a flange of a central dividing wall of serviceprovision ducting which has a double flange at the top of the centraldividing wall.

[0078] FIGS. 18-21 shows views of a second embodiment of straight wallcover part according to the present invention. It is similar in designto that shown in FIG. 8, but includes the following additional features.

[0079] A set of clips 53 are provided for engaging with the top of awall member of a section of service provision ducting.

[0080] A lip 54 is provided extending down from the edge of a coversurface 55. The lip 54 is for abutting against a corresponding lip ofanother cover part. A set of clips 56 are provided for engaging,together with the lip 54, the top flange of a central dividing wall of asection of service provision ducting, which dividing wall has a doubleflange at its top.

[0081]FIG. 22 is a sketch plan view showing how the internal angle coverpart of FIGS. 14-17 and the external angle cover part of FIGS. 11-13 canbe assembled together, with a corner piece 57 according to FIG. 29.

[0082]FIG. 23 is a view from the underneath of FIG. 22. It can be seenthat a further corner piece 57 according to FIG. 29 is included, the topof which abuts the lip 46 of the external angle cover part. Further,there is a corner piece 58 according to FIG. 28 which abuts the wallparts of the external angle cover part and a further corner piece 58according to FIG. 28 which abuts the lip 51 of the internal angle coverpart.

[0083] It should be noted that the internal angle cover part, the cornerpieces 58, the corner pieces 57 and the external angle part are notconnected together by any engaging means. FIG. 23 simply shows how theyshould be placed together. In use, clips, 44, 43, 47, 48, 52 engage withthe tops of wall members of sections of service provision ducting (notshown) and the upper flanges of a central dividing wall of sections ofservice provision ducting which have a double flange at the top. Thecorner pieces rest in the sections of service provision ducting.

[0084]FIG. 25 shows how a straight wall cover part according to FIGS.18-21 may be combined with two internal angle cover parts according toFIGS. 11-13 to form a flat T, together with a pair of corner pieces 58according to FIG. 29. FIG. 24 shows the under side of the flat T of FIG.25. It can be seen that there is an additional pair of corner pieces 58according to FIG. 28. In a similar manner to FIGS. 22 and 23, there isno mechanical connection between the part shown in FIG. 24. They areinstead connected together by mutual engagement with sections of serviceprovision ducting (not shown). Clips and lips of the internal anglecover parts and the straight wall cover part engage with the upperflanges of service provision ducting, in a similar manner to FIGS.22-23, and will not be described further below.

[0085] FIGS. 26 shows how four internal angle cover parts according toFIGS. 11-13 can be combined to form a cross-over, together with fourcorner pieces 57 according to FIG. 29.

[0086]FIG. 27 shows the under side of FIG. 26. It can be seen that thereare additional four additional corner pieces 58 according to FIG. 28. Ina similar manner to FIG. 22, 23, 24 and 25, there is no mechanicalconnection between the parts shown in FIG. 27. They are connectedtogether due to their common engagement with service provision ducting(not shown) the internal angle cover parts engage with service provisionducting via the clips described in relation to FIGS. 11-13 above andwill not be described further.

[0087]FIG. 28 is a plan view of a corner piece 58 for use with thepresent invention. It comprises a curved surface 60 of a radius ofcurvature which is not less than a predetermined value. Thispredetermined value will be fixed by the design of fibre optic cable tobe used and normally falls in the range 25-75 mm, typically around 50mm. The corner piece further comprises a pair of ribs 61 which extendfrom the rear face of the corner piece. Each ribs 61 has a straightedge. In use, the rib 61 allow the corner piece to be firmly placedagainst the wall members of sections of service provision ducting.

[0088]FIG. 29 shows a corner piece 57 for use with the presentinvention. It comprises a curved surface 62 which extends throughapproximately 270°. The radius of curvature of the curved surface 62 isnot less than a predetermined value. The predetermined value is fixed bytype of fibre optic cable to be used and is normally in the range 25mm-75 mm and typically around 50 mm. A pair of ribs 63 project from arear surface of the corner piece 57 for engagement against wall membersof sections or service provision ducting, to hold the corner piecefirmly in position.

[0089]FIG. 30 is a sketch isometric view of the corner piece 57 of FIG.29. It is viewed from below. The curved surface 62 and a rib 63 can beseen. It can be seen that the lower edge of the curved surface 62 isnotched at 64. This is to allow the corner piece to be fitted into thebottom of service provision ducting which comprises engagement membersextending from the floor member. The corner piece 57 is then held inposition resting only on the ends 65 and a specially provided foot 66.

[0090]FIG. 31 is a sketch isometric view of the corner piece of FIG. 28.The curved surface 60 and ribs 61 can be seen. FIG. 31 is a view fromabove. A pair of notches 67 can be seen. These are provided to extendover longitudinally extending engagement members which project from thefloor member of the trunking.

[0091] The present invention has been described above by way of exampleonly and modifications can be made within the invention. The inventionalso extends to any individual features described or implicit herein orany modifications or any combination or generalisation of any suchfeatures.

1. A corner or junction assembly comprising at least two sections ofservice provision ducting meeting at an angle, each section comprising alongitudinally extending floor member and at least one longitudinallyextending wall member projecting from the floor member, the floormembers of the sections of service provision ducting being substantiallycoplanar, and adjacent sections of service provision ducting definingbetween them an angle, a cover part being providing extending from eachangle up to, but no further than, the centre line of the respectivesections of service provision ducting.
 2. A method of assembling acorner or junction assembly for service provision ducting, comprisingplacing at least two sections of service provision ducting at an angleto one another, each section comprising a longitudinally extending floormember and at least one longitudinally extending wall member projectingfrom the floor member, the floor members of the sections of serviceprovision ducting being substantially coplanar and adjacent sections ofservice provision ducting defining between an angle, the method furtherincluding the step of inserting a cover part which extends from eachangle up to but no further than the centre line of the respectivesections of service provision ducting.
 3. A corner or junction assemblyaccording to claim 1, being a flat T, flat bend or flat crossover.
 4. Acorner or junction assembly according to claim 1, wherein the sectionsof service provision ducting meet substantially at a right angle.
 5. Acorner or junction assembly according to claim 1, comprising at least aninternal angle cover part, comprising a corner surface and a coversurface extending from the corner surface.
 6. A corner or junctionassembly according to claim 1, a corner piece being provided extendingbetween two sections of service provision ducting, the corner piececomprising a surface having a first end lying on the wall member of thefirst section of service provision ducting and a second end lying on awall member of the second section of service provision ducting, and acurved section of radius not less than a value in the range 25-75 mmjoining the first and second ends of the corner piece.
 7. A componentfor a corner or junction assembly as defined in claim 1, the componentcomprising a corner surface and a cover surface extending from thecorner surface, whereby in use, the corner surface is located in theangle between two adjacent sections of service provision ducting and thecover section extends from the angle up to but no further than thecentre line of the respective sections of service provision ducting. 8.A kit of parts for forming a corner or junction assembly according toclaim 1, comprising at least four internal angle cover parts, at leastone external angle cover part and at least one straight wall cover part,whereby selected ones of the cover parts may be assembled selectively toform a flat bend, flat T or flat crossover.